The SXSW 2012 Movies You Need to See

Some of the geekiest movies of 2012 are debuting at South by Southwest this week. We talked to some of the filmmakers and actors behind the titles we're most excited to see this year. Check back here as we update the story with more movies.

The Cabin in the Woods

The Cabin in the Woods

The less you know going into Drew Goddard's The Cabin in the Woods the better. From the trailer, we can glean that the movie, which premiered at this year's SXSW film festival, starts as your typical horror film: Five college kids take a weekend getaway to a remote cabin, meeting all the stereotypical characters from horror films along the way. But then we cut to a facility where men in suits watch surveillance monitors from cameras hidden around the cabin. Just why these men are watching is unclear—but soon, Cabin becomes everything fans could ever want in a horror film but never knew they could have. "I can't say there was a lot of thought that went into, oh, is this a horror movie, is it a sci-fi movie, is it a comedy," says Goddard, who co-wrote the film with Joss Whedon. "We just started with something that sounded fun to us and went from there."

There are two sides to The Cabin in the Woods: The cabin, and what Goddard calls the B-side, or the high-tech facility, houses the mysterious operation keeping tabs on the cabin's inhabitants. The look of the facility was based on an unlikely source. "I grew up in Los Alamos, N.M., which is where they built the atomic bomb," Goddard says. "So much of the design and the technology on that side came from my childhood. I took pictures of the Manhattan Project and what they were wearing and gave it to the designer and said here, make my hometown."

Wherever possible, Goddard tried to use practical effects in Cabin, which often led to amusing moments on set. "We have a part of the movie where a body part hits the camera," Goddard says. "It's amazing how hard it is to get a bloody body part to hit a camera. We had three different people—one on either side of the camera, and one above—batting the body part around and splashing blood on the camera just out of frame so it looked like the body part was hitting the camera directly. And the amount of math and science that went into something that was so silly just delighted me to no end. It was so much fun."

Initially announced in 2008, Cabin foundered for years as part of MGM's bankruptcy. During that time, it was announced that the film would be converted to 3D—which never happened, much to Goddard's delight. "I love 3D when it's done right, and we never planned on this being a 3D film," he says. The Cabin in the Woods will finally hit theaters April 13.

21 Jump Street

21 Jump Street

In 21 Jump Street, based on the popular ‘80s TV show, cops Schmidt and Jenko go undercover at a local high school to bust a designer-drug ring. But when their secret identities get mixed up, Schmidt (the smart nerd) has to participate in a play with the popular kids, and Jenko (the jock) has to go to science class—AP (Advanced Placement) chemistry, to be exact. "I included science in the story because even though I always found math and chemistry difficult, I had really good friendships with the kids who were great at that stuff," screenwriter Michael Bacall says. "I see in our popular culture there's been this tendency to marginalize the people who really affect our lives and our chances for survival everyday, and these are the people who are the scientists and the doctors and the math kids in high school, and that's always driven me kind of nuts."

Throughout the course of 21 Jump Street, Jenko (Channing Tatum) actually begins to see that science is cool—and even uses what he's learned in class in a pivotal moment in the film. "It was so fun for me to try to figure out what they could learn that we could apply in an action context, and chemistry was it. One of the directors, Chris Miller, is much better at chemistry than I am, so I had this concept that we could use learning chemistry to create a great action beat at the end, and he very much helped me out with what actually would be involved in that."

What's involved, Miller and his co-director Phil Lord told Popular Mechanics in an email, is Jenko creating a homemade bomb out of lithium batteries, gunpowder, and schnapps. "He scores lithium batteries from a camera with a knife to get past the safety layer," Miller says. "He drops the scored lithium batteries and gunpowder from shotgun shells into a half-empty bottle of Schnapps, which contains water and sugar, and he seals the top and shakes it. Both KNO3 (potassium nitrate) and lithium are oxidizers, and lithium when it touches water will react violently and cause a reaction, creating hydrogen gas. Alcohol is highly flammable, and if it gets hot enough, the H2 will combust in a big way. The KNO3 in gunpowder accelerates the combustion. Being sealed creates pressure to add to the combustion."

Miller acknowledges that "It probably would have been good to talk to an actual chemist about it instead of relying on my fading AP chemistry memories, but hey, it's the magic of the movies."